Benzene phosphonic acid esters

ABSTRACT

The purpose of the invention are new benzene phosphonic acid compounds in which two to four benzene nuclei are bound together and which contain one to three phosphorus atoms. The new compounds are free acids, their salts with anorganic cations, their esters, thioesters or amides. The invention concerns also the manufacture of these benzene phosphonic acid compounds and their use for the stabilization of organic materials.

United States Patent Hoger et a]. Dec. 23, 1975 [54] BENZENE PHOSPHONIC ACID ESTERS [56] References Cited [75] Inventors: Kurt Hoger, Muenchenstein; UNITED STATES PATENTS cuenfihel' Tscheulin, Rienhen, both 3,061,583 10/1962 l-luhn et a]. 260/962 ux of Switzerland [73] Assignee: Sandoz Ltd., Basel, Switzerland Primary Examiner-Anton H. Sutto Attorney, Agent, or Firm-Gerald D. Sharkin; Richard [22] Filed. Apr. 25, 1974 E. Vila; Thomas C. Doyle [21] Appl. No.: 463,864

Related US. Application Data [57] ABSTRACT Continuation-impart Of Ser. N0. 191,079, Oct. 20, The purpose of the invention are new benzene phos- 1971' phonic acid compounds in which two to four benzene nuclei are bound together and which contain one to [30] Forelg" Apphcatlon Pnomy Data three phosphorus atoms. The new compounds are free Oct. 22, 1970 Switzerland 15605/70 acids, their salts with anorganic cations, their esters, June 30, 1971 Switzerland 9597/71 thioe ter or amides, The invention concerns also the manufacture of these benzene phosphonic acid com- [52] US. Cl. 260/962 ound and their use for the stabilization of organic [51] Int. Cl. C07F 9/46 i l [58] Field of Search 260/962 14 Claims, N0 Drawings BENZENE PHOSPHONIC ACID ESTERS This application si a continuation-in-part of our copending application Ser. No. l9l,079 filed Oct. 20, l97l now U.S. Pat. No. 3,825,629.

The purpose of the invention are new benzene phosphonic acid compounds in which two to four benzene nuclei are bound together and which contain one to three phosphorus atoms. The new compounds are free acids, their salts with anorganic cations, their esters, thioesters or amides. The invention concerns also the manufacture of these benzene phosphonic acid compounds and their use for the stabilization of organic materials.

The invention relates to a process for the production of new benzene phosphonic acid compounds of formula wherein m means 1 or 2, nsubstituted or substituted diphenyl or terphenyl,

Q the single bond or an unsubstituted or substituted phenylene radical, X a radical of formula and X hydrogen or a radical of formula (Ila) R R R and R independent of each other stand for hydrogen or an unsubstituted or a substituted hydrocarbon radical, containing up to 16 carbon atoms,

Y for oxygen, sulfur or the radical of formula N (III) Z and Z, either bound to R, together with the N atom, for a heterocyclic ring or for R R R or R.,, which process is characterized by the reaction of 1 mol of a compound of formula wherein Hal means halogen and X hydrogen or a radical of formula P (Hal),

H, as Hal-radicals are present in the compound of formula (IV).

The starting materials of formula (IV) used in the present invention are new. They are produced from unsubstituted or substituted aromatic hydrocarbons, which are composed of 2, 3 or 4 benzene nuclei, bound together by a single bond. Examples for such hydrocarbons are: Diphenyl, 0-, mand pterphenyl, m quaterphenyl, pquaterphenyl, 1,2,4-triphenyl-benzene and l,3,5-triphenyl-benzene. From these starting materials the compounds of formula (IV) are produced by reaction with a phosphorus trihalide, preferably with phosphorus trichloride. This reaction can be performed at very high temperatures in the gaseous phase. To avoid side-reactions it is, generally, advantageous to work under milder conditions, using catalysts. Friedel- Crafts-Catalysts are suitable, especially anhydrous aluminium chloride. One preferably works with a surplus of phosphorus trichloride at its boiling temperature. Working up the reaction mixture, the aluminium chloride complex withthe dichlorophosphine is first decomposed, for instance with phosphorus oxychloride or with pyridine. Principally these methods of manufacture are known. These and other analogous procedures for the production of compounds of formula (IV) are collectively described by K. Sasse in Handbuch von Houben-Weyl, Methoden der organischen Chemie, 4th Edition (1963), Vol. XII/l, organische Phosphorverbindungen, part 1, pages 302-318.

The starting materials, characterized by formula (VI), are: Water, hydrogen sulfide, ammonia, alcohols, phenols, mercaptans, thiophenols and organic primary and secondary amines.

The /reaction of the starting materials of formulae (IV) and (VI) normally proceeds easily; to avoid sidereactions, it is often necessary to smooth the vehement reaction by cooling externally. Reacting with water, it is preferred to use it in surplus, to cool and to add the halophosphine of formula (IV) so slowly, that the temperature does not rise too high by the exothermic reaction. Accomplishing the hydrolysis in this way, there result colorless, powdery compounds, containing radicals of the following structure:

These derivatives of the benzene phosphonic acid have acid properties and, by treating with inorganic bases or with salts containing anorganic cations, are transferred in their corresponding salts. Examples for such anorganic reagents are: Calcium hydroxide, zinc-oxide, sodium carbonate, potassium hydrogen carbonate, aluminium acetate, barium chloride, nickel acetate and zinc chloride. The hydrolysis of halophosphines of formula (IV) and the transformation of the hydrolysis products, which contain radicals of the above formulae (VIIa) or (VIlb) into their salts, may also be performed in a one step process. For this purpose, as described above, the water used for the hydrolysis is put in surplus in advance, together with the desired inorganic reagent, followed by the halophosphine of formula (IV), which is slowly added by stirring. Humidity is carefully excluded if, instead of water, other compounds of formula (VI) are to be reacted. Generally phenols react smoothly if heated for instance to ll50C, whereby the hydrogen halide splits off.

Acid binding agents, such as pyridine or trialkylamines can be added to bind the split off hydrogen halide.

This method is preferred if alcohols are reacted. 1f the compounds of formula (IV) are reacted with organic amines or with ammonia, these are used in a surplus, which serves as a binding agent for the hydrogen halide split off.

The described reactions are analogous processes, which are generally known. A respective collective summary has been published in the afore-mentioned book by K. Sasse (compare p. 318 ff.).

Substituents in the olyphenyl compounds, characterized by the symbol [formulae (1) and (1V)], in the phenylene radical Q and also as radicals R [formulae (11) and (VI)] and Z[formula (111)] are alkyland cycloalkyl groups. Examples for such substituents are: Methyl, ethyl, propyl, butyl, isobutyl, amyl, 2,2-dimethylpropyl, octyl, dodecyl, isopropyl, tert.-butyl, 2,6,8- trimethyl-4-nonyl, 2-ethyl-hexyl, 2,4,6,8-tetramethylnonyl, cyclododecyl.

The preferred polyphenyl compounds and the phenylene radical Q are unsubstituted; they may be substituted by halogen, especially by chlorine and bromine or by alkoxy radicals such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, hexyloxy, dodecyloxy and Z-ethylhexyloxy.

Besides the abovementioned hydrocarbon radicals which can stand for R and Z, the latter can also mean aryl radicals, which as well as the alkyl radicals, may be substituted. Examples are the following substituents: Phenyl, 2-, 3- or 4-methylphenyl, dimethylphenyl (mixture of isomers), p-tert.butylphenyl, 2-methoxyphenyl, 3-chlorophenyl and dichlorophenyl (mixture of isomers), 2-methoxyethyl, 2-methoxypropyl, 2-phenoxyethyl, 2-(2-phenoxyethoxy)-ethoxy, 2-cresoxyethyl, benzyl, 4-chlorobenzyl, 2,4-dichlorobenzyl, 2-chloroethyl and substituents of formula CH;,(OCHCH2),,

wherein p means one of the numbers 2 to 12.

Examples for those cases, in which the radicals Z and R are connected with each other and form, together with the N-atom [formula (111)] a heterocyclic ring, are the heterocyclic substituents pyrrolidino, piperidino, hexamethylenimino and morpholino.

The invention also concerns the new compounds of formula (1) and their use as stabilizers.

For this purpose the new compounds are either incorporated in the product or material sensitive to light, oxygen and heat, or applied to its surface to form a protective film. By their stabilizing effect they protect these sensitive substances from degradation. They have a wide range of application in the processing of plastics; to name some examples, they can be employed as stabilizers for cellulose acetate, cellulose proprionate, cellulose acetobutyrate, polyethylene, polypropylene, polyvinyl chloride, polyvinyl chloride-acetate, polyamides, polystyrene, ethyl cellulose, cellulose nitrate, polyvinyl alcohol, silicon rubber, melamineformaldehyde and urea-formaldehyde resins, allyl cast resins, polymethylmethacrylate, polyesters and polyacrylonitrile. The

compounds can also be used to protect natural products such as rubber, cellulose, wool and silk from degradation.

The products or materials for protection may be present in the form of sheet or film, panels, tubing, rods, tapes, coatings, fibres, granules, powders or other solid forms, or as solutions, emulsions or dispersions. The stabilizers are incorporated in, or applied to these materials by the known methods. One of the main methods of application is intimate mixing of the stabilizer and the plastic material, e.g. polypropylene granules, in a kneading or other suitable machine and extrusion moulding of the mixture. This technique ensures homogeneous blending, which is important for effective protection. Extrusion moulding is employed to produce a variety of products, including films, tubing and filaments. The latter can be converted into woven fabrics.

1f polypropylene, for instance, is to be processed as woven fabric the stabilizer is normally mixed with it prior to extrusion as filament yarn. However, these new stabilizers can be applied with equally good effect to textile yarns and fabrics, for example from an aqueous bath containing the compound of formula (1) in superfine dispersion. Textiles of polyester and cellulose acetate fibres are suitable for this exhaust method of application.

The plastics need not necessarily be polymerized when the new compounds are added. The latter can be blended with the monomers or prepolymers prior to the condensation or other polymerization reaction yielding the final polymer.

Besides their use for the stabilization of clear films, plastics and the like, the new stabilizers are suitable for application in or on opaque, semi-opaque and translucent materials having a surface which is subject to degradation by light, oxygen and heat. Examples of such materials are foamed plastics, opaque film and sheeting, opaque papers, transparent and opaque pigmented plastics, fluorescent pigments and automobile and furniture polishes, creams, lotions and similar products, which latter group of products may be opaque, clear or translucent. Benzene phosphonic acid esters and their stabilizing effect are known from literature. Comparing these compounds, for instance with those described in the Belgian Pat. No. 724,802, the new compounds of formula (1) have essential advantages. They are less fugitive, have less inclination for migration and are better soluble in many materials to be protected. Moreover the connection of at least two benzene nuclei in the new compounds of formula (1) has the effect, that they absorb ultra violet rays. They therefore do not only protect against heat and oxygen but also against the decomposition of sunlight. Any comparable phosphorus compounds have none such combined protective effect. In spite of this polyvalent effect it is in many cases advantageous to mix the new stabilizers with other types of light absorbers or of stabilizers.

Those mixtures of agents have often a synergistic effect and protect the treated materials at the same time in a particularly high degree against ultra violet light, heat and oxydative desintegration.

As explained above the new compounds of formula (1) can be used as stabilizers for various organic materials. Depending the kind and number of the substituents the compounds of formula (1) are more or less suited for the protection of a certain organic material. The

following relations between the chemical constitution of the compounds of formula (I) and plastics, which have to be protected, have for instance been observed: To protect polypropylene, such agents are especially suited, which contain one or several aliphatic or cycloaliphatic radicals which contain at least 6, preferably 8 to 20 carbon atoms. To protect polyvinylchloride such agents are especially suited, whose substituents R contain aryl radicals, which may be substituted with lower alkyl radicals or with chloro atoms. For the protection of polyesters and of polyamides those agents are especially suited which contain several ether groups in the substituents R.

The present invention concerns also the materials which contain compounds of formula (I) for stabilization. As shown above in some examples, the incorporation of the new compounds into the materials that need protection can be effected at any stage of processing according to known methods, whereby the amount of added protective agents may vary within wide limits, for instance between 0.01 and preferably between 0.05 to l related to the materials that need protec-.

tion.

In the following examples F means melting point; Kp boiling point; A wavelength, A max the wavelength of maximum light absorption in nanometer units; parts and per cents are by weight and temperatures in de-:

grees centigrades.

EXAMPLES FOR THE PRODUCTION OF THE INTERMEDIATE PRODUCTS OF FORMULA (IV) 'chlorophosphine) of formula are obtained in the form ofa red, light oil of a pungent smell.

c. In the absence of moisture. a solution of 34.5 parts of p-terphenyl, 330 parts of phosphorus trichloride, and 52 parts of aluminium chloride are heated under reflux during the course of 5 hours; 61.3 parts of phos- E phorus oxychloride are subsequently added and the mixture is stirred for a further 15 minutes, is cooled to 0, the resulting Al-complex is filtered off, is washed with phosphorus trichloride, and thef ltrate is evaporated in a vacuum.

As residue 29 parts of 4,4"-(p-terphenyl)-bis-(dic1 1 PO12 I) are obtained in the form of light yellow crystals.

Examples for the end-products of formula (I) are listed in the following table I where the melting points 'of crystalline compounds are indicated in column F. These compounds melt at a temperature considerably higher than room temperature. The other indicated compounds are specified in column F as oil. )tmax. means the maximum of light absorption which is expressed by nanometeer (nm) units. The constitution formulae indicated in table 1 are confirmed by elementary analyses.

Table 1 Ex. Constitution of the compounds of general formula I F )tmax. No. (nm) Rt l OC,I-I R R,- oil 252 2 OC,;I-I (iso) R =R oil 250 4; 5... "F9" 19 -o c,u, oil 254 ,5 "T m m 9" i9 OC H, (iso) on 253 6 -S--C, H R R 42-43 270 7 R =R ll0-lll 255 Table l-continued Ex. Constitution of the compounds of general formula I F kmax. No. (nm) 26 SC, I-I R, R 63-65 308 27 -s-@+ R,=R 187-189 310 28 N c,H, R, R, oil 296 The symbols signify the tertiary butyl radical.

Examples for the production of end-products of formula (I) The Examples are numbered in the same way as the corresponding compounds of the above table 1.

Example 7 In the absence of moisture a solution of 43.5 parts of 4-diphenyldichlorophosphine [Example a), formula (IX)] in 100 parts of toluene is added at O5 to 56.8 parts of 4-tert.butyl thiophenol and 35 parts of triethylamine in 200 parts of toluene; the mixture is allowed to react over night at 40, the precipitated triethyl ammonium chloride is filtered off, the filtrate is evaporated in a vacuum, and the oily residue is purified by crystallization from methanol-ether. Constitution formula and characterization of this compound and the compounds of the production Examples cited below are indicated in the above Table 1.

Example 9 In the absence of moisture a solution of 28.35 parts of 4,4-diphenyl-bis-(dichlorophosphine) [Example b), formula (X)] in 100 parts of chlorobenzene is added at 0-5 to 23.6 parts of n-butanol and 32 parts of triethylamine in 300 parts of chlorobenzene; the mixture is allowed to react over night at 40, the precipitated salt is filtered off, the filtrate is evaporated in a vacuum, and a light yellow oil is obtained.

EXAMPLE 13 A solution of 47.5 parts of 4,4-diphenyl-bis-(dichlorophosphine) in 100 parts of toluene is added at 05 to 117.5 parts of 4-nonylphenol and 55 parts of triethylamine in 400 parts of toluene; the mixture is allowed to react overnight at 5060, the precipitated triethyl ammonium chloride is filtered off, the filtrate is evaporated in a vacuum, and thus, a yellow viscous residue is obtained.

The same compound is also obtained by mixing the starting materials without triethylamine and without toluene and gradual heating to l40-l60, while there is passed carbon dioxide through the mixture, until the evolution of hydrogen chloride ceases.

EXAMPLE 15 A solution of 20.0 parts of 4,4-diphenyl-bis-(dichlorophosphine) in 100 parts of toluene is added at 0-5 to 45.4 parts of dodecyl mercaptan and 22.8 parts of triethylamine in 200 parts of toluene; the mixture is then allowed to react over night at 40, the precipitated triethyl ammonium chloride is filtered off, the filtrate is evaporated in a vacuum, and the residue is crystallized from ether. i

EXAMPLE 27 A solution of 31.0 parts of 4,4"-(p-terphenyl)-bis- (dichlorophosphine), Example c), formula (XI), is added at 05 to 48.1 parts of 4-tert.butyl thiophenol and 30.1 parts of triethylamine in 300 parts of toluene; the mixture is allowed to react over night at 40, the precipitated triethyl ammonium chloride is filtered off, the filtrate is evaporated in a vacuum, and the residue is crystallized from benzene-methanol.

In place of 30.1 parts of triethylamine, 24 parts of anhydrous pyridine may also be used as acid-binding agent. 7

In Examples 4, 5, l4, l8, 19, 20, 21, and 25 oftable I there are mentioned esters of phosphonic acids which contain in the same molecule radicals derived from different alcohols, phenols or mercaptans. The production thereof is effected'in analogous manner as described in the above production Examples by reacting the chlorphosphines with a mixture of the corresponding reaction partners. Thus, mixtures of esters are always obtained; aside from the main constituents which are characterized by the formulae of Examples 4, 5, l4, l8, 19, 20, 21, and 25 these mixtures also contain other esters, wherein the equivalent ratio of the radicals is shifted.

The following Examples relate to end-products which are obtained by hydrolysis of 4,4'-diphenyl-bis' dichlorophosphine) of formula (X), partly as free phosphonic acids, partly in the form of the salts with inorganic cations.

Example 29 a parts of 4,4'-diphenyl-bis-(dichlorophosphine) of formula (X), produced as described in Example-(b), are diluted with 20 parts of chlorobenzene and slowly added to 300 parts of water while stirring well, and the temperature is kept at 0-5 by externalcooling. The reaction iscompleted at 20 after 18 hours. The thin colourless precipitate is filtered off and is dried at in a vacuumThe obtained crude product is appropriate for the use as stabilizer. It mainly consists of the compound of formula and impurities which probably consist of anhydrides of the acid of formula (XII). Other impurities furthermore contain chloride, as a small part of the chlorine atoms in the starting product of formula (X) has escaped from hydrolysis by coating with the insoluble precipitate.

Example 30 The process described in Example 29 may be simplified by renouncing the isolation of the intermediate product of formula (X) as well as the purification thereof (precipitation of the aluminium chloride by phosphorus oxychloride).

46.2 parts of diphenyl, 106 parts of aluminium chloride, and 165 parts of phosphorus trichloride are heated under reflux during the course of 2 hours; the excess of phosphorus trichloride is subsequently removed by distillation and the viscous residue is taken up in 40 parts of chlorobenzene. Hydrolysis is then effected with 300 parts of water as described in Example 29. The obtained fine colourless powder contains 16.7 of phosphorus, l.l of chlorine, and 3.8 of aluminium.

EXAMPLE 31 The 4-diphenyl-dichlorophosphine of formula (IX) described in Example a) is hydrolized in accordance with methods described in Example 29; after the working up a colourless fine powder is obtained which mainly consists of the compound of the following for- Example 32 26 parts of the compound obtained in accordance with Example 29 are mixed by stirring with a solution of 21 parts of barium chloride in 100 parts of water and boiled under reflux during the course of 3 hours.After cooling to the colourless precipitate is filtered, is washed with water and is dried at 90 in a vacuum. The resulting barium salt contains 18.9 of barium.

ln analogous manner the light green nickel salt (content of nickel is is obtained from 25 parts of nickel acetate and the colourless zinc salt (content of zinc is 4.1 from 27 parts of chloride of zinc.

Example 33 Proceeding in manner analogous to that described in Example 30 the resulting colourless powder is suspended in 400 parts of water while stirring; calcium oxide is gradually added at such an amount that after stirring at for a longer period the pH value does not sink below 5; the mixture is cooled to 5 and the precipitate is filtered. The resulting colourless salt contains 4.1 of calcium, 6.3 of aluminium, and 3.3 of chlorine.

Examples for the use of end-products of formula (I) A. Stabilization against oxidative degradation A few of the compounds cited in the above Examples are tested in view of their effect as stabilizers against oxygen as follows: 0.1 of a compound of formula (I) are homogeneously incorporated in polypropylene which contains 0.2 of 4,4-methylen-bis-(2,6-d'i-tert- .butylphenol) as antioxydant agent. After displacing the air, the plastics in the form of thin small plates is then kept under oxygen in a closed system. Then it is heated to whereby an overpressure of about 20 mm Hg takes place. The oxidation of the plastics results in a decrease of pressure. The rate of this decrease of pressure is small if the effectiveness of the stabilizer or the mixture of the stabilizers is high. The test results are summarized in the following Table 2. The figures signify the time expressed in minutes which passes until the overpressure decreases to zero.

Table 2 Incorporated phosphorus compounds of formula (I) Exple No. minutes l 19 29 I79 30 193 31 200 32 (Ba salt) 229 32 (Ni salt) 207 32 (Zn salt) 290 33 195 In a further series of tests 0.07 of 4,4-methylenbis-(2,6-di-tert.butylphenol) and 0.13 of dilaurylthiodipropionate were used for the fundamental stabilization of the polypropylene and for the rest checked comparatively as described above. The results are summarized in the following Table 3.

B. Stablization against brownish discoloration While incorporating 0.2 of the stabilizer 2,2- methylen-bis-(4-methyl-6-tert.butylphenol) in polypropylene at about 220 a brownish discoloration takes place. This discoloration may be avoided if 0.1 of a compound of formula (I) is incorporated at the same time.

In the ageing of small plates of polypropylene in a furnace at 140 a strong'brownish discoloration takes place after only one day if the plastics only contains 0.2 of 2,2'-methylen-bis-(4-methyl-6-tert.butylphenol). If the plastics furthermore contains 0.1 of a compound of the above table 1 it remains colourless after 4 days at 140. Formulae of representative benzene phosphonic acid compounds of the foregoing examples are as follows:

Example 3 weeewy Example 16 Example 26 nislor -2. i

2. A compound of claim 1, wherein n is 1.

3 A compound according to claim 1 wherein any aryl portion of R or R is phenyl.

4. A compound according to claim 1 wherein Y is sulphur.

5. A compound of claim 1, wherein R and R are independently alkyl or alkylaryl.

6. A compound of claim 1, wherein Y is oxygen.

7. A compound of claim 1, wherein n is l, Y is oxygen or sulphur and R, and R are independently alkyl or alkylaryl.

8. A compoundof claim 7, of the formula OCH 9. A compound of claim 7, of the formula o-c n (1.50)

10. A compound of claim 7, of the formula Example 31 What is claimed is: l. A compound of the formula R and R are each, independently, a hydrocarbon radical of up to 16 carbon atoms selected from the group consisting of alkyl, cycloalkyl, aryl, alkylaryl and arylalkyl, Y is oxygen or sulphur, and

MP\O C9HH (E) 11. A compound of claim 7, of the formula 12. A compound of claim 7, of the formula 14. A compound of, claim 7, of theformula UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,928,510

DATED December 23, 1975 |NV ENTOR(S) Kurt Hofer/Guenther Tscheulin It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On title page, underneath the heading "United States Patent"; change "Hoger et al." to

--Hofer et al.--.

On title page, after the heading "Inventors";

change the name "Hoger" to --Hofer--.

Signed and Scaled this Twenty-fifth Day of September I979 [SEAL] Arrest:

LUTRELLE F. PARKER Arresting Officer Acting Commissioner of Patents and Trademarks 

1. A COMPOUND OF THE FORMULA
 2. A compound of claim 1, wherein n is
 1. 3. A compound according to claim 1 wherein any aryl portion of R1 or R2 is phenyl.
 4. A compound according to claim 1 wherein Y is sulphur.
 5. A compound of claim 1, wherein R1 and R2 are independently alkyl or alkylaryl.
 6. A compound of claim 1, wherein Y is oxygen.
 7. A compound of claim 1, wherein n is 1, Y is oxygen or sulphur and R1 and R2 are independently alkyl or alkylaryl.
 8. A compound of claim 7, of the formula
 9. A compound of claim 7, of the formula
 10. A compound of claim 7, of the formula
 11. A compound of claim 7, of the formula
 12. A compound of claim 7, of the formula
 13. A compound of claim 7, of the formula
 14. A compound of claim 7, of the formula 